Methicillin-resistant Staphylococcus aureus: risk assessment and infection control policies

The endemic state of methicillin-resistant Staphylococcus aureus (MRSA) occurs through a constant influx of MRSA into the healthcare setting from newly admitted MRSA-positive patients, followed by cross-transmission among inpatients and an efflux of MRSA from the hospital with discharged patients. To date, most MRSA prevention strategies have targeted cross-transmission among hospitalised patients. Intensive concerted interventions that include isolation can reduce the MRSA incidence substantially. However, debate continues about the cost-effectiveness of infection control policies, including screening protocols, to control the influx of MRSA into hospitals. The rationale and cost-effectiveness of wide screening, as compared to targeted screening, should be further studied using appropriate statistical approaches and economic modelling.